To improve the design or quality of automotive decoration or the like, many different decorated parts of a vehicle (i.e. console box, instrument panel, arm-rest or the like) are practically used, and such decoration is added to the surface of a resin compact. As a method for enhancing the decoration of decorated parts, the hydraulic-transfer method is generally used. The hydraulic-transfer method is a technique in which a special film with some predetermined design (i.e. a wood-grain pattern, a geometric pattern or the like) is floated on the water surface to transfer the designs to the surface of the resin compact by water pressure. This technique makes it possible to print the designs three-dimensionally onto the surface of the part.
As a decorative method other than the hydraulic-transfer method, the laser-printing method is known. Laser printing is a decorative method in which a laser is irradiated onto the surface of a part. The surface of the part then changes by the heat of the laser so as to print the designs onto the surface. As such, this decorative method makes it possible to print the designs at a low cost compared to the hydraulic-transfer method. In addition, the inventor of this invention considers another method for decorating by laser-drawing the surface of a component, such as a gradation-processing method of grading the marks of the laser drawing, thus increasing the accuracy of the designs of the vehicle-interior components
Patent Document 1 shows a method for manufacturing a translucent thin-film solar cell of which the exterior has a translucent appearance gradated by laser processing. Specifically, this thin-film solar cell is placed on a supporting unit that is inclined at a predetermined angle. Then the distance between the laser-focal point and the processing point of the solar cell is changed temporarily to form a translucent opening or hole on the solar cell, in which case the wider the distance between the laser-focal point and the processing point, the smaller is the translucent opening or hole on the solar cell. As such, the gradation is made on the translucency (transmittance) of the solar cell.